Genetic variation and geographic differentiation among populations of the nonmigratory agricultural pest Oedaleus infernalis (Orthoptera: Acridoidea) in China.

The nonmigratory grasshopper Oedaleus infernalis Saussure (Orthoptera : Acridoidea) is an agricultural pest to crops and forage grasses over a wide natural geographical distribution in China. The genetic diversity and genetic variation among 10 geographically separated populations of O. infernalis was assessed using polymerase chain reaction-based molecular markers, including the intersimple sequence repeat and mitochondrial cytochrome oxidase sequences. A high level of genetic diversity was detected among these populations from the intersimple sequence repeat (H: 0.2628, I: 0.4129, Hs: 0.2130) and cytochrome oxidase analyses (Hd: 0.653). There was no obvious geographical structure based on an unweighted pair group method analysis and median-joining network. The values of FST, θ(II), and Gst estimated in this study are low, and the gene flow is high (Nm > 4). Analysis of the molecular variance suggested that most of the genetic variation occurs within populations, whereas only a small variation takes place between populations. No significant correlation was found between the genetic distance and geographical distance. Overall, our results suggest that the geographical distance plays an unimpeded role in the gene flow among O. infernalis populations.

[Construction of expression vector of hTERT/hIL-18 fusion gene in eukaryotic cells and its function].

OBJECTIVE: To construct expression vector of hTERT-hIL-18 fusion gene in eukaryotic cells and to study its biological function. METHODS: hIL-18 gene was amplified by RT-PCR, then T-A cloned and inserted into PCDNA3.1(+)/hTERT vector. The sequence of fusion gene was examined by enzyme incision and DNA sequencing. The vector with fusion gene was transformed into 3T3 cells by the method of lipofecting, and proved by Western blot. The secretion gamma-interferon was measured with ELISA and cell apoptosis was detected with flow cytometry. RESULT: Expression vector PCDNA3.1(+) of hTERT/hIL-18 fusion gene was constructed successfully. The correct sequence was proved by enzyme incision and sequencing and there was a correct open reading frame. Fusion protein of hTERT/hIL-18 was effectively expressed in eukaryotic cells and was proved by Western blot and immunofluorescence stain. The fusion protein stimulated KG-1 cells to secrete gamma-interferon and had anti-apoptosis effect. CONCLUSION: Fusion protein hTERT-hIL-18 is highly effectively expressed in eukaryotic cells and is biologically active.